From the German public document No. 2,138,747, a kind of weighing device has become well known in which one or several scales run around on a continuous track which constitutes a part of the conveyor line. This track can be shaped according to the known layout, like a carousel or like a hanging conveyor. In the carousel-like layout it is provided with several scales, and a transfer conveyor is provided which pushes the products from the delivery conveyor onto the carousel, while another transfer conveyor transfers the products from the carousel onto the removal belt conveyor.
The apparatus requires a large number of scales which, especially with highly-tempered and/or dirt-shedding products, are endangered with respect to their operation due to their direct contact with these products. The kind of transfer as well as the necessity of placing the products exactly on the scales are difficult to carry out, especially if the mass produced articles do not arrive on the conveyor in an exact sequence.
In this public document, it is further explained that it is known how to use belt scales with a weighing belt which, for example, can be formed as a gridiron. However, it is also explained there, that with such belt scales, the weighing of relatively light mass produced articles of high temperature with the required precision is impossible.
In the present invention, however, the weighing device is arranged in the angle formed between the conveyor belts. It has a weighing belt driven by and carried by a weighing cell. A transfer conveyor extends over both conveyor belts and the weighing belt. The delivery conveyor is preferably the removal conveyor of an automatic glass-blowing machine and the removal conveyor is preferably the delivery conveyor that belongs to the cooling oven. Between these, a transfer is necessary in any case, so that no additional complication of the transport procedure results because of the weighing procedure. Especially with automatic glass-blowing machines, constant precise weight check is necessary because the feed of glass drops to the molds changes in the course of the operation. Since the glass molds determine only the outer shape, the thickness of the walls and the capacity of the containers vary in size. That can lead to unallowably great variances in the filling amount when the bottles are later filled, and further, it is not possible to make relatively thin-walled bottles without endangering the shatter-index.
The precise weight check is needed in order to be able to subsequently regulate the glass feeder unit of the automatic machine as a function of the bottle weights. Previously all the attempts to make a precise and reliable weighing device failed, because the extreme environmental (temperatures in the neighborhood of red-heat, strong air turbulences and extreme dirtiness) have hindered them. It has turned out, however, that these problems can be solved by means of the device and assembly in accordance with the invention.
The weighing apparatus can then be arranged in a closed housing, out of which the weighing belt extends from the side. The weighing apparatus which stands in the angle formed between the two conveyor belts, which is not normally used in the rest of the operation can therefore be built sufficiently large and can be enclosed by a housing advantageously insulated and provided with a high pressure ventilation.